You don’t need 15 playable guys. Most rotations are between 9-12 players. So Alex has 11 he needs one maybe two more and he be fine. Maybe a true PG and maybe one more big. I know they are looking internationally right now.
There is even the possibility Alex doesn’t fill all 15 spots. I do think he fills at least two more spots and he start next season with a minimum of 13 which is plenty.
One thing you have to remember is he didn’t recruit position specific players. Most on the roster can play two or three different roles or positions. So 11 can look like 13 or 14 with all the flexibility.
This team is about athletes the can play and defend multiple spots